In the related art, in the processing such as an etching, a deposition, an oxidation, and a sputtering in a manufacturing process of a semiconductor device such as an IC, an LSI, and a VLSI, a flat panel display (FPD) such as a liquid crystal display or the like, plasma has been widely used in order to perform a satisfactory reaction on a processing gas at a relatively low temperature.
For example, in the etching process of a semiconductor device using a silicon wafer, a plasma etching apparatus of a high frequency discharge type is used.
However, in the plasma etching apparatus, a phenomenon occurs in which etching characteristics in a center section of the silicon wafer are different from etching characteristics in an outer periphery portion of the silicon wafer.
Thus, in order to equalize the etching characteristics of the silicon wafer in a plane, placing a focus ring having an annular shape on the outside of the silicon wafer has been carried out so as to surround the silicon wafer.
However, even in a case of using the focus ring, when the plasma etching is performed on the silicon wafer, a temperature difference is generated between the center section of the silicon wafer and the outer periphery portion thereof, and a difference between an etching rate in the center section of the silicon wafer and an etching rate in the outer periphery portion thereof is generated due to the temperature difference.
In such a case, there has been a problem in that a state is generated where an etching result in the surface of the silicon wafer is non-uniform, and thus yield characteristics of the obtained semiconductor device decline by the non-uniformity of the in-plane processing shape due to the etching.
In order to solve the problem, a plasma etching processing apparatus of a magnetron type is suggested in which a temperature detector is placed near a surface of an inner portion of a focus ring without being exposed to the surface (Patent Document 1).
In the plasma etching processing apparatus, the temperature of the focus ring is detected at all times by the temperature detector, the temperature of the focus ring is controlled so as to be maintained at the same temperature as that of the silicon wafer by performing the temperature controlling of the focus ring. Thus, a difference in surface reaction of a radical between on the silicon wafer and on the focus ring is suppressed, a fluctuation in the etching rate in the plane of the silicon wafer is suppressed, and the uniformity of the etching is improved.